Mindy,
I also had retrosigmoid for a previously radiated tumor. I didn't have any useful hearing left at the time of surgery, but my neurosurgeon specializes in retrosigmoid. Like Dr. Friedman, he said that with retro the facial nerve is exposed last. In his opinion with translab it is exposed too soon, making it more vulnerable.
Because my tumor was large, and had been radiated, all the doctors I had consulted with gave me very poor chances of hearing preservation. However Dr. Akagami was able to save my facial nerve - I woke up with very light facial weakness, unnoticeable, which went away within a few weeks. I had a very good recovery, no balance issues and no headaches. My only complaint was the sore neck and shoulder, which was due to a previous injury that was aggravated by the positioning during surgery. This took quite a few months to improve.
I know you are also concerned about the TN. I didn't have TN, but my trigeminal nerve was impacted by the tumor, causing facial numbness, metallic taste and dry eye. After surgery the symptoms fluctuated for a while, and then completely disappeared. I have been told that the trigeminal nerve is very resilient and can heal over time. So for sure there is hope that your TN could resolve.
I think that if you eventually decide to have surgery Dr Friedmann will be an excellent choice.
Marianna